One Pair Beta 22 Class A Headphone Amplifier Kit / β22 Headphone Amp Board DIY
This list is for 2 channle kit / boards.
DIY KIT: will need yourself to solder and adjust it.
Assembled board: we will solder & adjust it well before shipping.
Each amp PCB Size: 155mm*50mm *1.6mm
Works voltage: +/-DC28V to +/-30V
| Measured results (sigma 22 PSU +/- 30V) | |
|---|---|
| Impedance Input |
50K with input volume potentiometer set to maximum 47.6K ohm |
| Impedance Output | Than less 0.01, 20KHz - 20Hz |
|
Output voltage Maximum 1KHz prior, to onset of clipping at |
43Vp-p (15.2Vrms) unloaded 38Vp-p (13.4Vrms) into 32 |
| Output Power |
Into 0.75Wrms 300 Into 5.6Wrms 32 Into 18Wrms 8 |
| Response Frequency |
0dBV output at 2.5MHz - +0dB, -3dB 0Hz |
| Time Rise |
Square wave at, 43Vp-p output 100KHz, 10% to 90% 175nS |
| Rate Slew |
Square wave at, 43Vp-p output 100KHz 198V/ mu S |
|
Level Noise Range Dynamic Harmonic distortion Total Distortion Intermodulation Crosstalk Stereo |
Overview from AMB:
β22 ("beta 22") is a high-end, reference-quality DIY stereo amplifier for dynamic headphones. It could also be built as a power amplifier for speakers (18Wrms into 8Ω unbalanced, or 50Wrms into 8Ω fully-balanced), or as a preamplifier.
The all-discrete (no integrated circuits), fully complementary and cascoded topology, high-current MOSFET output stage, full class A operation and carefully tuned operating points provide vanishingly low distortion, high speed, wide bandwidth, low output impedance, and high output power. All elements of the design were critically examined to create an amplifier that performs as well on the test bench as it does with music. Please see the Tech highlights section for a detailed description.
The β22 is the result of a community service project for the audiophile hobbyist. The schematic diagram is open source. The circuit design, as well as the printed circuit board layout are the work of AMB with participation from the DIY community. It is designed to be relatively easy to build, but it is not recommended as a first-time project for the beginner.
The β22 project is primarily centered around the main amplifier board. Each board supports one channel. You may build the β22 in one of the following configurations:
*Conventional 2-channel "passive ground" amplifier (2 boards needed)
*3-channel "active ground" amplifier (3 boards needed)
*4-channel "fully balanced" amplifier (4 boards needed)
To build a working amplifier, you will also need a regulated DC power supply to provide power to the board(s),we have the following Power supply board for β22 headphone amplifier.
Sigma22 regulated power supply board for this amp:
https://www.ebay.com/itm/125762845145
Power Transformer link:
https://www.ebay.com/itm/125762822969
If you buy the amp board + Power supply board + power transformer. we can provide combine shipping. please contact us for the real shipping costs. Thanks.
